The present invention relates to a scanning apparatus; and more specifically, it relates to an apparatus for scanning sheets containing a source original image retained on a contact plate in applications such as in image forming apparatus.
A conventional scanning device installed in an image forming apparatus such as a copying machine includes a transparent plate for retaining original sheets; an optical system disposed below the plate for scanning the original material; a size-detection arm having original sheet-size detection sensors; and a fan for introducing cooling air into the space under the plate.
Because the scanning apparatus plate becomes heated by flare of the optical system, cooling air is supplied beneath it by the fan in order to reduce the plate temperature.
Under applications requiring high-speed copying, however, the optical system successively scans original material with such frequency that the plate heats considerably. Accordingly, a fan having a greater blowing capacity should thus be required in order to increase effective cooling. Disadvantageously, greater space would be occupied by employing a therefore larger fan, consequently increasing overall size of the scanning apparatus.